Strong suppression of emission quenching in core quantum dots coupled to monolayer MoS.

Non-radiative processes like energy and charge transfer in 0D-2D semiconductor quantum dot (QD)-transition metal dichalcogenides (TMDs) and other two-dimensional layered materials, like graphene and analogs, leading to strong quenching of the photoluminescence (PL) of the usually highly emissive QDs, have been widely studied. Here we report control of the emission efficiency of core QDs placed in close proximity to the monolayers of MoS. The QDs are transferred in the form of a high-density compact monolayer with the dot-dot separation, as well as the MoS-QD separation, , being controlled through chemical methods.

Evolution of inter-layer coupling in artificially stacked bilayer MoS.

In this paper, we show experimentally that for van der Waals heterostructures (vdWh) of atomically-thin materials, the hybridization of bands of adjacent layers is possible only for ultra-clean interfaces. This we achieve through a detailed experimental study of the effect of interfacial separation and adsorbate content on the photoluminescence emission and Raman spectra of ultra-thin vdWh. For vdWh with atomically-clean interfaces, we find the emergence of novel vibrational Raman-active modes whose optical signatures differ significantly from that of the constituent layers.

Evaluation of potential antiamnesic activities of aqueous extract of Vitex trifolia leaves against scopolamine induced amnesia and in normal rats.

Background: The goal of this study was to evaluate the cerebroprotective and cognition-enhancing activities of the aqueous Vitex trifolia (Vt) L. (Verbenaceae) leaf extract against scopolamine-induced amnesia and in normal rats.

Methods: Reference or working memory and long-term memory in rodents were tested by experimental paradigms like passive avoidance (PA) and T-maze (TM), respectively.